Chap. V] TROPICAL DISTRICTS WITH DRY SEASONS 355 



effective, and occasion a richer differentiation in the kind of vegetation 

 covering the soil than in West Java, where the vegetation appears to be 

 practically dependent on climate only. Particularly in East Java there 

 occurs on soil that easily dries up or that is comparatively impervious, 

 the djati-forest formation, a typical tropophilous deciduous forest. 



The djati-forest owes its name to the economically valuable djati-tree, 

 Tcctona grandis — the teak-tree (Fig. 190), which has a wide distribution over 

 continental India, yet only in Java forms pure forests in which other trees 

 occur merely as subsidiary species. The teak-tree is by no means a giant, 

 either in height or in thickness of stem. It is at most 25 meters high. 

 Its cordate leaves, reminding one of those of Catalpa, are very large, and 

 the violet flowers, that open in the middle of the rainy season, are arranged 

 in pyramidal panicles. The trunk possesses a light coloured bark and is 

 devoid of epiphytes ; on the other hand, figs (species of Urostigma) 

 frequently colonize the branches. During the dry season (June until 

 October) the teak is quite leafless and displays its new leaves in November 

 with the advent of the west monsoon. 



Cordes has given a detailed description of the oecology and the flora of 

 the natural djati-forest of East Java — artificial teak-forest occurs in West 

 Java, as well as in British India. 



In contrast with the rain-forest of West Java the appearance of the djati- 

 forest is very different at different seasons of the year. In August and 

 September, at the height of the dry season, the picture the forest presents 

 is almost wintry. The vast majority of the trees, among them especially 

 the teak-tree, are quite leafless, and the ground is covered by a rustling 

 layer of their dry leaves, which do not decay until the rainy season. The 

 trees accompanying the teak are more recognizable in the dry season than 

 during the rains. Acacia leucophloea is known by its umbrella-shaped 

 crown ; Albizzia procera by its bark resembling that of birch. Some 

 trees remain green, among them the commonest companion of the teak, 

 Butea frondosa, which in contrast with the teak adorns itself at the height 

 of the dry season with its large fiery papilionaceous flowers. Evergreen 

 also are the sapindaceous Schleichera trijuga, the mimosaceous Albizzia 

 stipulata, with a regular umbrella-shaped crown, and the fig-trees perched 

 on the branches of other trees. 



Between the tall trees numerous smaller ones grow, especially Emblica 

 officinalis, Gaertn., a euphorbiad, also Dillenia aurea, and other plants. 

 Palms are very rare, bamboos occur here and there. Shrubby vegetation 

 is richly developed and varied. The Leguminosae are specially numerous, 

 for instance Acacia tomentosa, Willd., species of Cassia, Papilionaceae ; but 

 Hibiscus Lampas also frequently shows its large yellow flowers. The 

 lianes are all thin-stemmed and chiefly Papilionaceae, such as Abrus pre- 

 catorius, species of Mucuna, and the like. The herbs vary greatly according 



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